Three MSP players were sent off and the club was disqualified from the tournament while Petone elected not to continue. A number of teammates accompanied him to seek medical attention, along with his mother, who watched events unfold from the sideline.
An eyewitness (himself a senior player from another club) told the Herald the young player was hit from behind and attacked while he lay on the ground.
"It was the most vicious and dog-pack-mentality act I've seen in any game ever," he said.
"It was honestly the most disgusting thing I've ever seen in rugby."
On the club's Facebook page, Petone chairman Wayne Smith told members the young man was checked after having CT scans.
"His eye was damaged but thankfully he is expected to regain sight," he said.
"While emotions have been running high we ask everyone to leave (the) matter to the appropriate channels. The Petone Rugby Club and the...whanau would like to thank everyone for the many texts and calls received from concerned people. We also appreciate the support shown from fellow clubs. Kia Kaha."
Wellington Rugby CEO Matt Evans said the union has offered support to the family and the clubs involved. He said Petone and MSP were fully cooperating with the police and WRFU would reserve further comment until the investigation was complete.
"We strongly condemn any form of violence in our game and are extremely disappointed anytime something like this occurs. Our immediate thoughts are with the injured player and ensuring he has the necessary support around him as he recovers from his injuries," said Evans.
MSP chairman Rob Evans said his club would wait for the official judicial process to play out before deciding on any further action it might take.
Evans said the thoughts of everyone at the MSP club were with the player and his family and that some of his side's players had visited him the day after the attack.
Three players from MSP and one from Petone have been stood down from all rugby activity pending the results of the WRFU's judicial process.
